1. Field
The following description relates to a high-capacity content service and a high-capacity content sharing method that are based on a network. As the high-capacity content is divided and transmitted, a validation system may verify integrity of each segment of the divided content.
2. Description of Related Art
A digital signature is one of a plurality of representative schemes that may be used to authenticate a source of data that is transmitted via a network and may provide data integrity. The digital signature may compress data using a one-way hash function to compress the date to be a predetermined size, and may perform a predetermined operation using a private key of a user. The private key may be a signature key through a public key cryptosystem that is used to generate a signature value. The signature value may be verified based on the corresponding public key.
In general, a high capacity multi-media file may be divided into fragments or segments that are a predetermined size through a fragmentation process to transmit the high capacity multi-media file. The fragments of the divided multi-media file may be separately stored and managed in a plurality of hosts, for example, in a distribution structure such as a Peer-to-Peer (P2P) structure. However, one or more of the segments may be forged or falsified during a cache and forward process. To detect the forgery or falsification, a scheme that includes a digital signature of a publisher in a multi-media file has been proposed. If a file is divided into a plurality of segments, the integrity of each segment and whether a corresponding segment is a part of the multi-media file should be verified.
A fragmented content verification method based on a Merkle Hash Tree scheme is one of a plurality of schemes that has been proposed to achieve the above verification.
However, in the Merkle Hash Tree scheme, a witness and a signature value are transmitted together with a segment each time the segment is transmitted, and thus, a transmission load is increased. In addition, when the segment is received, a hash value is repeatedly calculated until the number of repeated calculations is a depth of a hash tree−1, and the signature value is verified, and thus, a calculation load is further increased.